Accelerator of vulcanization



Patented Au ie, 1943 i'arry L. Fisherfstamford, Conn i assignor to QU. S. Industrial Alcohol 00,, New York, N. Y.,

'- Y a corporationof West Virginia 7 7N0 Drawing. Original application May 7,1941. Serial No. 392,346. Divided and this applica non November 25194-1, Serial 0.420,2s'

3 Claims. (01. 200-491) vThis invention relates .toa'n'ew organic com pound, to the'method of preparing it, and .to its practicalapplication,especially as an accelerator of vulcanization of rubber. This new organic.

substance has various advantageous uses'in the rubber and other industries. Y

It is the object of the invention to provide a newand useful organic compound, a'practical method of preparing it and an economical and satisfactory application of the compound in the vulcanization of rubber.

Other objects and advantages of the invention will be apparent as it is better understood by refercnce to the following specification, in which the preferred embodiments of the invention are described. y

The invention pertains particularly to 4,4,6- trimethyl-2-thiotetrahydro 1,3,2-oxazine which is the product of the reaction of diacetonalkamine (4-amino-4-rnethy1-2-pentanol) and carbon disulfide.

The reaction probably takes place in accordanc with the following equation:

7 CH3 CH3 0E2 CH3.(-).CH2.0H.CH3+CS2 KOH o cnonwngs I NH: on EN 0 A typical example of a method of preparation of the substance is as follows:

Sixteen grams of potassium hydroxide are dissolved in 200 cc. of absolute alcohol, and 98 grams of diacetanolkamine l-amino--methyl I From these results it appears that the reaction.

. and a white molded stock. In the tread stock it:

is seen-that although theirmolecular weights are close together, namely 159 and16'7, 1' part of the 2-pentanol) and 88 cc. of carbon disulfide-slowly added with stirring. After this mixture has stood for about 1 hour, it is heated under reflux for 7-8 hours on the steambath. During this heating hydrogen sulfide gas. is evolved, and crystals of the product form in the mixture. The

mixture is allowed to cool to room temperature.- The crystals are then filtered ofi and washed with a' small amount of cold water. The yield of the oxazine is 125 grams, which is 94% of the theoretical amount. The melting point of the crude product is 208 C., and after recrystalization 210- 11 C., uncorrected. 1

The substance is soluble in hot glacial acetic acid and hot acetone; slightly solublein cold glacial acetic acid, acetone and dioxane; and practically insoluble in ous alkalies.

alcohol, water and'aque- Analysis of the purified substance gave the'lol lowing results? I Calculated for Found C7H13ONS 1 Percent Per ce-nt Carbon 52.79 ,4 53.10 Hydrogen 8. 23 8. 38 Nitrogen 8. v 8. 76 Sulfur 20. 13 20.00 Molecular weight (by Rasts method).....! 159. 24 152 goes as indicated above and that the structural formula of the substance is correct as given.

The oxazine shows marked action as an accelerator of vulcanization. Below is given a comparison of the action of the oxazine and a wellknown commercial accelerator, me'rcaptobenzothiazole, popularly called Captax, in a tread stock oxazine is as potent as 1.5 parts oiCaptax. It is also useful in latex compounds;

Thetests were on unaged stocks. The cures are given in the number of minutes .at thedesighated pounds per squar inch of steam pressure.

T represents the tensile strength in pounds per square inch and E the per cent elongation, both at break. 1

' Tread stock T-50 at 350% r T-50 at 500% A B" D :3 3:0 5 it: 31; -12. a 8. 6 :g-g 'g lg? :13 Z 12I4 -15I4 it m ld to While I have described the preferred method of preparing the new compound it is to be under- O D stood that the invention is not limited thereby v r V "and that I claim the use of the compound in its Pale crepe 100 100 various applications other than vulcanization of X X72 zinc oxid 10 i0 rubber. {gggmw '88 This; application is a division of application igiig g 1 Ser'. No.392,346 filed May 7, 1941. The mama-.-. IIIIIIIIIIIIIIIII: 0.6 I Flaim: j Oaptax j 10 65 .7 ;1.;Atcomp osition comprising rubber and 4,4,6-

' trimethyl 2ethio tetrahydro-1,3,2-oxazine as an Tensile strengths and elongation's afic atm 0f v an at o 2th. process of producing vulcanized rubber v a a O D products which comprises treating rubber with a Cure f H vulcanizing agent and 4,4','6-trimethy1-2-thio T T E tetrahydro-1,3,2-oxazine; 3 A rubber stock comprising thevuicanization 660 1,600 643 product of'a rubberstock containing a vulcaniz- 3 ing agent and 4,4,6-trimethyi-2-thio-tetrahydro- 6101 21540 645 V 1,3,2-oxazihe; 1 j 3.0 a: V HARRY L. FISHER. 

